Benjamin Bernard

• PhD
• Professor (Associate) at National Polytechnic School

Sangay volcano (Ecuador) shows a quasi-continuous activity at least since the seventeenth century and has produced several eruptions which affected towns and cities at considerable distance (up to > 170 km). For this reason, despite its remote location, recent efforts were aimed at reviewing its volcanic history, quantifying the occurrence probabil...

The physiochemical properties of volcanic ash are determined by magma ascent and eruption dynamics and provide important insights into controls on the timing and style of volcanic eruptions. However, linking petrological observations to monitoring parameters remains challenging. Here we investigate the relationships between geophysical, geochemical...

The 2018 eruption of Sierra Negra volcano, Galápagos, Ecuador has provided new insights into the mechanisms of caldera resurgence, subsidence, and fissuring at basaltic shield volcanoes. Here, we integrate local (∼0.4 km) seismo‐acoustic records and regional (∼85 km) infrasound array data to present new observations of the 2018 Sierra Negra eruptio...

We assess the volcanic hazard posed by pyroclastic density currents (PDCs) at Tungurahua volcano, Ecuador, using a probabilistic approach based on the analysis of calibrated numerical simulations. We address the expected variability of explosive eruptions at Tungurahua volcano by adopting a scenario-based strategy, where we consider three cases: vi...

We present a tephra fallout hazard assessment of Sangay volcano, Ecuador. This volcano is under semi-permanent activity at least since the 17th century, and has produced several eruptions whose products have affected towns and cities at considerable distance (up to > 170 km). For this reason, despite its remote location, recent efforts have been ai...

Sangay volcano is considered as one of the most active volcanoes worldwide. Nevertheless, due to its remote location and low-impact eruptions, its eruptive history and hazard scenarios are poorly constrained. In this work, we address this issue by combining an analysis of monitoring data and historical chronicles with expert elicitation. During the...

Timely acquisition of ash cloud heights is crucial for aviation safety and forecasting volcanic ash dispersion and fallout. Since visual observations are not always available, we assess the suitability of retrieving ash cloud heights from brightness temperature and plume direction observed in GOES-16 satellite imagery, VOLCAT solutions, and Washing...

Crops are regularly impacted by tephra from explosive volcanic eruptions, causing significant economic losses and jeopardising farmers’ livelihood at the local to regional scales. Crop vulnerability to tephra remains poorly understood, impeding the construction of robust risk models for agriculture. Previous studies of crop vulnerability to tephra...

We assess the volcanic hazard derived from pyroclastic density currents (PDCs) at Tungurahua volcano, Ecuador, using a probabilistic approach based on the analysis of calibrated numerical simulations. We address the expected variability of explosive eruptions at Tungurahua volcano by adopting a scenario-based strategy, where we consider three cases...

The Instituto Geofísico (IG-EPN) was created in 1983 by faculty of the Escuela Politécnica Nacional, a public university in Quito, Ecuador, with the objective of assessing volcanic hazard in the country. Since then, the IG-EPN has established and developed an instrumental monitoring network and from 1999 has faced the eruption of five continental-a...

Sangay volcano is widely considered as one of the most active volcanoes worldwide. Nevertheless, due to its remote location and low-impact eruptions, its eruptive history and hazard scenarios are poorly constrained. In this manuscript, we addressed this issue by combining an analysis of monitoring data and historical chronicles with expert elicitat...

Pyroclastic density currents (PDCs) are hazardous and destructive phenomena that pose a significant threat to communities living in the proximity of active volcanoes. PDCs are ground-hugging density currents comprised of high temperature mixtures of pyroclasts, lithics, and gas that can propagate kilometres away from their source. The physical prop...

Breadcrust bombs formed during Vulcanian eruptions are assumed to originate from the shallow plug or dome. Their rim to core texture reflects the competition between cooling and degassing timescales, which results in a dense crust with isolated vesicles contrasting with a highly vesicular vesicle network in the interior. Due to relatively fast quen...

Crops are regularly impacted by tephra from explosive volcanic eruptions, causing significant economic losses and jeopardizing farmers’ livelihood at the local to regional scales. Crop vulnerability to tephra remains poorly understood, impeding the construction of robust risk models for agriculture. Previous studies of crop vulnerability to tephra...

Arc volcanism arises from the release of fluids from the descending slab, which enables melting in the mantle wedge by lowering the solidus temperature. Metasomatism—compositional alteration by fluids—of the mantle is known to have an important role in magma production in volcanic arcs over long spatial and temporal scales. However, the episodic er...

Stratovolcanoes are commonly characterised by cyclic eruptive activity marked by transitions between dome-forming, Vulcanian, Subplinian and Plinian eruptions. Guagua Pichincha volcano (Ecuador) has been a location of such cyclicity for the past ~ 2000 years, with Plinian eruptions in the first and tenth centuries AD (Anno Domini/after Christ), and...

On 2 December, 2021 we recorded a sequence of drumbeat seismic events at Sangay volcano. This sequence lasted several hours and resulted in two explosive emissions whose eruptive columns reached 9 km above crater. Unexpectedly, these explosions did not produce any ash fallout in the inhabited areas around the volcano. This drumbeat sequence was pro...

Volcanic ash is a hazard to human health and activities. Accurate and timely forecasts coupled with effective communication about the dispersion and fallout of volcanic ash during explosive events are essential to reduce impacts on local communities and limit economic losses. In this study, we present the first detailed description of an eruptive p...

Monitoring the evolution of lava flows is a challenging task for volcano observatories, especially in remote volcanic areas. Here we present a near real-time (every 12 h) and free tool for producing interactive thermal maps of the advance of lava flows over time by taking advantage of the free thermal data provided by FIRMS and the open-source R so...

In Ecuador, a country with several active volcanoes and with four eruptions in the last decade in the continental arc, it is very likely that high-voltage transmission lines cross volcanic hazard zones on their routes. Here, we quantify the impact of fresh volcanic ash from the hydromagmatic Cotopaxi-2015 and the magmatic Tungurahua-2016 eruptions...

The volcanoes of Galápagos, Ecuador, are among the most active in the world, with an average of five eruptions per decade. Monitoring and communication of their activity are essential for timely management of events. In this context, the Instituto Geofísico de la Escuela Politécnica Nacional carries out constant surveillance of Galápagos volcanoes...

Pyroclastic currents (PCs) and tephra fallout are among the major volcanic hazards at explosive volcanoes and have been widely studied over the past decades in order to model the physical processes controlling them. The aim of such efforts is using numerical models for producing probabilistic hazard maps, and complementing such maps with a quantifi...

Formalised elicitation of expert judgements has been used to help tackle several problematic societal issues, including volcanic crises and pandemic threats. We present an expert elicitation exercise for Piton de la Fournaise volcano, La Réunion island, held remotely in April 2021. This involved 28 experts from nine countries who considered a hypot...

Sangay is one of the most active volcanoes in Ecuador, as it has been almost continuously erupting at least since the seventeenth century. However, because of its remote location and low associated risk to human population, little is known about its eruptions. Here we summarize Sangay’s volcanic activity from January 2001 to May 2020, based on grou...

Plain Language Summary Magmatic gas released by intraplate, hot‐spot related volcanism can offer insight into the abundance and distribution of volatiles in the Earth's upper mantle. Unfortunately however, the available data set for hot spot magmatic gases is sparse and incomplete, due to relatively infrequent eruptions and the remote location of m...

Tephra fallout hazard assessment is undertaken with probabilistic maps that rely on numerical models. Regarding maps production, the input parameters of the model (including atmospheric conditions), the physical approximations of the numerical simulations, and the probabilities of occurrence of different eruption types in specific time frames are a...

In November 2019, the fourth Volcano Observatory Best Practices workshop was held in Mexico City as a series of talks, discussions, and panels. Volcanologists from around the world offered suggestions for ways to optimize volcano-observatory crisis operations. By crisis, we mean unrest that may or may not lead to eruption, the eruption itself, or i...

Hazard and risk communication requires the design and dissemination of clear messages that enhance people's actions before, during, and after volcanic crises. To create effective messages, the communication components such as message format and content, must be considered. Changes in technology are changing the way people communicate at an ever-inc...

Periglacial melting processes can provide the water source for secondary lahars triggered by volcanic and/or meteorological phenomena on volcanoes. Between December 2015 and April 2016, four major lahars were reported southeast of Chimborazo volcano (Ecuador). Fieldwork allowed determining the area (1.670.37 km2), volume (3E+05 to 7E+05 m3), peak...

The Billecocha plateau (4000 m a.s.l.) lies in the high elevation Ecuadorian Andes volcanic arc. It overhangs by 2000 m above the interandean valley. Both the plateau and surrounding volcanoes are heavily affected by active faulting characterized by straight, sharp and discontinuous scarps within a 6 km wide and 24 km long corridor. Contrasting int...

Future occurrence of explosive eruptive activity at Cotopaxi and Guagua Pichincha volcanoes, Ecuador, is assessed probabilistically, utilizing expert elicitation. Eight eruption types were considered for each volcano. Type event probabilities were evaluated for the next eruption at each volcano and for at least one of each type within the next 100...

During the last two decades, Sangay has been one of the most active Ecuadorian volcanoes. However, because of its remote location and logistically difficult access, monitoring Sangay is a challenging task. The IG-EPN tackled this problem by expanding its terrestrial monitoring network and complementing it with the available satellite data. On 7th M...

The use of numerical models aimed at producing probabilistic maps is becoming more and more a common practice for tephra fallout hazard assessment. However, it is important to complement such maps with a quantification of the major sources of aleatoric/epistemic uncertainties, to help stakeholders and decisionmakers in taking informed decisions. In...

Recent large basaltic eruptions began after only minor surface uplift and seismicity, and resulted in caldera subsidence. In contrast, some eruptions at Galápagos Island volcanoes are preceded by prolonged, large amplitude uplift and elevated seismicity. These systems also display long-term intra-caldera uplift, or resurgence. However, a scarcity o...

Breve descripción geológica y proceso de formación.

Large volcanic landslides and debris avalanches are rapid, water unsaturated, gravity-driven mass movements produced by the failure of one (or more) portion(s) of a volcanic edifice. In this chapter, we evaluated the current terminology used to describe this phenomenon. We propose a descriptive scheme based on metrics and geological features that a...

A new database of volcanic debris avalanche deposits (VDADs) from 594 volcanoes in 52 countries has been compiled based on published inventories and our own unpublished data. This work presents an overview of the distribution of VDADs around the world, their sizes, recurrence intervals, and a quantitative characterization of their controlling param...

The newest version of the Potential Volcanic Hazards Map of Guagua Pichincha Volcano (Third Edition) IG-EPN/IGM

Many volcanoes erupt compositionally homogeneous magmas over timescales ranging from decades to millennia. This monotonous activity is thought to reflect a high degree of chemical homogeneity in their magmatic systems, leading to predictable eruptive behaviour. We combine petrological analyses of erupted crystals with new thermodynamic models to ch...

The 14 July 2013 Vulcanian explosion at Tungurahua occurred after two months of quiescence and was extremely powerful, generating some of the highest infrasound energies recorded worldwide. Here we report on how a combination of geophysical data, textural measurements, and physical and mechanical tests on eruptive products allowed us to determine t...

Numerical modeling of tephra dispersal and deposition is essential for evaluation of volcanic hazards. Many models consider reasonable physical approximations in order to reduce computational times, but this may introduce a certain degree of uncertainty in the simulation outputs. The important step of uncertainty quantification is dealt in this pap...

Imbabura (4620 meters above sea level) is a large strato-volcano in Northern Ecuador that experienced dominantly effusive eruptions during the Upper Pleistocene. However, a remarkably violent explosive eruption took place at ca 30 ka cal BP, with emplacement of a "directed blast" deposit to the southwest of the main edifice. The eruption started wi...

In the paper entitled “Two independent real-time precursors of the 7.8 M earthquake in Ecuador based on radioactive and geodetic processes – Powerful tools for an early warning system”, Toulkeridis et al. (2019) claim that they found radiation and GPS signal anomalies before the April 16th 2016 Pedernales earthquake (Ecuador) and that their finding...

Guagua Pichincha volcano (4784m a.s.l.) is the youngest part of the Pichincha Volcanic Complex, a potentially active volcano, located on the Western Cordillera of the Ecuadorian Andes. It is a compound stratovolcano located at 12 km W of Quito (capital of Ecuador, with population of 3 million peole). The youngest eruptive center in Guagua Pichincha...

Volcanic ash clouds and their deposits represent the volcanic hazard with the furthest reach and a high potential socioeconomic impact. In order to reduce its effects, real-time monitoring and numerical model-based forecasting of ash clouds are critical. Since 1983, the Instituto Geofísico de la Escuela Politécnica Nacional (IG-EPN) has been monito...

Since the Mount St. Helens eruption in 1980, the study of volcanic debris avalanches has been a major topic in volcanology worldwide. Ecuador has a high concentration of volcanoes and many have been affected by giant landslides with a characteristic scar in the source area and a thick debris avalanche deposit at the foot of the volcano. In this wor...

Hazard maps constitute a guiding tool for land use planning and emergency response. Quito, the capital of Ecuador, is surrounded by several active and potential active volcanoes, such as AtacazoNinahuilca Volcanic Complex (ANVC). The geological record indicates that Plinian eruptions at ANVC have an average Frequency of one event every 2513±193 yea...

El complejo volcánico Cayambe representa una potencial amenaza para poblaciones que basan su economía en la floricultura. En este trabajo, se presenta: 1) modelar espacialmente escenarios de erupción del volcán, 2) modelar espacialmente el potencial impacto de estos escenarios de riesgos por afectación de lahares y de ceniza; y 3) evaluar los impac...

In the paper entitled “Two independent real-time precursors of the 7.8 M earthquake in Ecuador based on radioactive and geodetic processes – Powerful tools for an early warning system”, Toulkeridis et al. (2019) claim that they found radiation and GPS signal anomalies before the April 16th 2016 Pedernales earthquake (Ecuador) and that their finding...

The complex volcano of Cayambe in Ecuador represents a potential threat, especially for populations that base their economy in floriculture. In this work, we present: 1) spatially modeling the eruption scenarios of the volcano, 2) spatially modeling the potential impact of these risk scenarios by lahar and ash affectation; and 3) evaluate the socio...

Eruption style and dynamics are controlled by various parameters including magma supply rate, magma viscosity, volatile content, and the permeability of the conduit. Rapid changes of these parameters can significantly modify the hazards associated to the eruption processes and understanding their relationship with multiparametric geophysical monito...

The 1982 and 2015 eruptions were the first at Wolf volcano, Galápagos Archipelago, with eyewitness accounts and satellite imagery. Both eruptions were characterized by a rapid and intense initial phase, with multiple eruptive vents, leading to the formation of large ‘a‘ā lava fields and scarce pāhoehoe mostly associated with the waning phases. The...

The 2015 eruption of Wolf volcano was one of the largest eruptions in the Galápagos Islands since the onset of routine satellite‐based volcano monitoring. It therefore provides an excellent opportunity to combine geophysical and petrological data, to place detailed constraints on the architecture and dynamics of sub‐volcanic systems in the western...

The 1982 and 2015 eruptions are the first at Wolf volcano, Galápagos Archipelago, with eyewitness accounts and satellite imagery. Both eruptions are characterized by a rapid, intense initial phase and multiple eruptive vents leading to the formation of large ‘a‘ā lava fields with scarce pāhoehoe deposits, mostly associated with the waning phases. T...

After eight years of quiescence, Fernandina volcano experienced two short-lived eruptions, on 4 September 2017 and 16 June 2018. The eruptions were characterized by very short periods of unrest that started a few hours before the initiation of the eruptive activity. On the other hand, Sierra Negra volcano (Isabela Island) began a new eruptive perio...

Pyroclastic sedimentary successions record an eruptive history modulated by transport and depositional phases. Here, a field technique of outcrop impregnation was used to document pyroclastic sediments at the scale of individual laminae. The details so obtained have the potential to reveal new insights into the dynamics of transport and deposition...

Pyroclastic currents are catastrophic flows of gas and particles triggered by explosive volcanic eruptions. For much of their dynamics, they behave as particulate density currents and share similarities with turbidity currents. Pyroclastic currents occasionally deposit dune bedforms with peculiar lamination patterns, from what is thought to represe...

Guagua Pichincha Volcano (GGP) is the active eruptive center closest to Quito and is located only 12 km SW of the city center. In 1999-2001 it had moderate eruptive activity (VEI 2) with the formation of eight domes that exploded, collapsed and formed ash columns that were directed to the W-NW and eastward, depositing two cm of ash over Quito. Due...

Cotopaxi volcano, located 60 km southeast of Quito and 45 km north of Latacunga, is one of the largest active stratovolcanoes in Ecuador. Its proximity to cities and its long eruptive history justify revisiting its hazard assessment. Cotopaxi debris avalanche occurred approximately 4.5 ka and corresponds to one of the largest events in its recent h...

The poster is about dynamics of Cotopaxi volcano debris avalanche and Chalupas ignimbrite role in its ocurrence.

The Ecuadorian arc comprises at least 84 Plio-Quaternary volcanic centers ¹, with 24 of them considered as potentially active (eruptive activity during the Holocene)². In addition, 21 volcanic centers that form the Galapagos Islands were considered in our study where 13 are potentially active. Moderate-to-large eruptions have a high recurrence rate...

Ecuador’s last severe volcanic disaster occurred 141 years ago when lahars from Cotopaxi destroyed several villages and part of Latacunga causing thousands of victims. 24 volcanoes in Continental Ecuador and 13 volcanoes in Galápagos are considered as potentially active. Since 1983, the IG-EPN works to create a monitoring network able to detect vol...

After eight years of quiescence, Fernandina volcano experienced two short-lived eruptions, on 4 September 2017 and 16 June 2018. The eruptions were characterized by very short periods of unrest that started a few hours before the initiation of the eruptive activity. On the other hand, Sierra Negra volcano (Isabela Island) began a new eruptive perio...

Pyroclastic currents are catastrophic flows of gas and particles triggered by explosive volcanic eruptions that share much of their dynamics with particulate density currents and turbidity currents. They occasionally deposit dune bedforms with peculiar lamination patterns, from what is thought to represent the dilute, low concentration, and fluid-t...

Through integration of multiple data streams to monitor volcanic unrest scientists are able to make more robust eruption forecast and to obtain a more holistic interpretation of volcanic systems. We examined gas emission and gas geochemistry and seismic and petrologic data recorded during the 2015 unrest of Cotopaxi (Ecuador) in order to decipher t...

Assessing hazard associated to volcanic ballistic projectiles is essential to limit fatal incidents close to erupting vents. Current state-of-the-art methods using high-speed visual and thermal images and volcanic radars permit to obtain high resolution information during explosive events but are limited to few laboratory volcanoes. Nowadays, long-...

The Ecuadorian arc comprises at least 84 Plio-Quaternary volcanic centers distributed along the Andes, with 24 of them considered as potentially active (eruptive activity during the Holocene). Moderate-to-large eruptions have a high recurrence rate and a high long-term probability. In addition, 21 volcanic centers that form the Galapagos Islands we...

Submission 1256 The Cotopaxi 2015 eruptive phase: insights from gas and glass Cotopaxi volcano (5,897 m) is located 50 km south of Quito, the capital of Ecuador. In April 2015, a progressive increase in the amplitude of transient seismic events initiated volcanic unrest. Starting on May 20, an increase in SO2 emissions from ~500 t/d to ~3000 t/day...

Submission 617 Subduction dynamics, mantle and crustal processes at arc volcanoes, investigated by relative CO2/ST abundances and 3He/4He isotope signatures. The investigation of the relative abundance of volatiles allows for a better constrain of the origin and recycling efficiency of these elements via subduction. Here, we attempt to correlate al...

Most volcanic hazard studies focus on magmatic eruptions and their accompanying phenomena. However, hazardous volcanic events can also occur during non-magmatic unrest, defined as a state of volcanic unrest in which no migration of magma is recognised. Examples include tectonic unrest, and hydrothermal unrest that may lead to phreatic eruptions. Re...

Varios periodos eruptivos han ocurrido durante el Holoceno en los Andes Septentrionales. En busca de sus evidencias, se realizó una perforación manual en el flanco sureste del volcán Cerro Negro, en la zona de Potrerillos, frontera Ecuador - Colombia. En el testigo de perforación se identificaron 12 capas de cenizas volcánicas con tamaño de grano m...

Cotopaxi volcano, Ecuador, experienced notable restlessness in 2015 that was a major deviation from its normal background activity. Starting in April and continuing through November 2015 strong seismic activity, infrasound registry, hikes in SO2 degassing and flank deformation with small displacements were some of the geophysical anomalies that wer...

The information comprised in the “Ecuadorian Volcanic Events and Geochonological” database allow us to make an overview of the eruptive frequency in the Ecuadorian arc. The recurrence rate of explosive eruptions was calculated by the mathematical methods of (1) linear regression of the cumulative number of events and (2) statistical analysis of eru...

The information comprised in the “Ecuadorian Volcanic Events and Geochonological” database allow us to make an overview of the eruptive frequency in the Ecuadorian arc. The recurrence rate of explosive eruptions was calculated by the mathematical methods of (1) linear regression of the cumulative number of events and (2) statistical analysis of eru...

Eruptive scenarios at Cayambe volcano and building of an event tree): Cayambe is an active stratovolcano located in the Eastern Cordillera (Ecuador). Due to its frequent Holocene activity and recent unrest, we propose to update the eruptive scenarios in order to improve hazard assessment. In addition to the two scenarios (S2 and S3) used to create...

EVOLUTIVE MODEL OF CHILES VOLCANO. The recent seismic activity registered in the Chiles-Cerro Negro area, motivated a new investigation in order to have a better knowledge of the development of this volcano. The present work describes the evolutionary model for the Chiles volcano, which is based on the analysis, study and interpretation of the petr...

Delimitation of lahar hazard zones in the western drainages of Cayambe volcano: Cayambe is an active volcano located in the Cordillera Real. The city of Cayambe, which has ~39.000 inhabitants, extends along the western's flank. Since mid-2016 signs of volcanic unrest have been recorded by the Instituto Geofísico (IG). Additionally, " andinistas " h...

The length of the insulators strings determines the insulation level of electric transmission towers. The electrical insulators behave differently depending on environmental conditions. Particle pollution is one of the most important to consider for the degradation of electrical insulation but it is difficult to estimate. Recently, Cotopaxi and Tun...

Analysis of the composition and texture of ash ejected during eruptive episodes can provide valuable information about magma storage and ascent conditions. After 73 years of repose, Cotopaxi volcano erupted after approximately four months of precursory activity that included an increase in seismicity, gas emissions, and minor ground deformation. Hi...

The Ecuadorian Volcanic Arc includes at least 84 Plio-Quaternary volcanoes, most of them having a long and complex eruptive history. We created a comprehensive database on Ecuadorian volcanic events compiling available geochronological and volcanological information published in journal articles, books, reports, conference proceedings, thesis and o...